Abstract: A medium pressure preparative liquid chromatography (MPLC) was used to isolate the aloins A and B and isoaloeresin D from Aloe vera simultaneously for the first time. The crude material extracted by acetone, was performed with ODS column (40 cm×26 cm, 30-50 μm) by using isocratic elution with methanol-0.5% acetic water (33:67, v/v) as the mobile phase at a flow rate of 20 mL/min. The detecting and collecting wavelengths were set at 254 nm and 356 nm, respectively, and the column temperature was room temperature. Three compounds were identified as aloins A and B and isoaloeresin D by using UV, IR, MS and NMR, and their purities were 98.0%, 96.0% and 98.9%, respectively. The method was convenient, and active constituents with high purity could be obtained simultaneously, which provided conditions to investigate the constituents and their activities of Aloe vera.

Key words: Aloins A and B, isoaloeresin D, medium pressure preparative liquid chromatography (MPLC)